BOB HIRSHON (host):
How fluoride works. I’m Bob Hirshon and this is Science Update.
Fluoride makes teeth harder and more resistant to acids produced by bacteria that live on our teeth. That helps prevent tooth decay. But physicist Karin Jacobs and her colleagues at Saarland University in Germany found that there’s more to the story than just that. Recently, they measured how much force it takes to remove harmful bacteria from teeth treated with fluoride compared with untreated teeth. They found that fluoride makes it much harder for bacteria to hold on.
KARIN JACOBS (Saarland University):
When you brush your teeth and you use fluoridated toothpaste, then the efficiency of toothbrushing is much higher because the bacteria don’t stick as hard.
She says it’s not yet known which plays the bigger role in preventing tooth decay – fluoride’s tooth-hardening effects, or its ability to make bacteria lose their grip. I’m Bob Hirshon, for AAAS, the science society.